public void AddSingleDestinationTest()
{
Airplane test = new Airplane("Test", 4, 6, 100, "t1");
Airplane test2 = new Airplane("Test2", 1, 2, 100, "t2");
Airplane test3 = new Airplane("Test3", 4, 6, 100, "t3");
test.AddSingleDestination(test2, 60);
Assert.AreEqual(1, test.ReachableNodes.Keys.Count);
test.AddSingleDestination(test3, 50);
Assert.AreEqual(1, test.ReachableNodes.Keys.Count);
}